Rotary kiln.



A. SOHAPPER.

ROTARY KILN.

APPLICATION FILED NOV. 2, 1910.

i w? if r Patented Jan. 13, 1914.

Snvemfoz 1;???" amen:

AXEL SCHAFFER, F COPENHAGEN, DENMARK.

ROTARY KILN.

Lil-84,170.

Specification of Letters Patent.

Patented Jan. 13,1914.

Application filed November 2, 1910. Serial No. 590,268.

[0 all whom it may concern Be it known that I, AXEL Sorrlirrnn, a subject of the King of Denmark, residing in the city of Copenhagen, Denmark, have invented certain new and useful Improvements in Rotary Kilns, of which the following is a specification, reference being had to the accompanying drawings, forming a part hereof.

This invention relates to rotary kilns such as are employed in the burning of cement and for other purposes. The lower or discharge end of such kiln is necessarily open for its full diameter in order that the clinker or other burned material may be discharged continuously over the lower edge of the rotating cylinder. During the operation of burning the lower open end of the cylinder must be closed so as to prevent the too free access of air by a suitable closure which is so constructed as to permit the discharge of the clinker or other burned material and the introduction of the powdered, gaseous or liquid fuel and the necessary volume of air to support combustion. The closure must also be capable of being moved aside in order to give access, when necessary, to the interior of the kiln. Furthermore, it is desirable that the air which is admitted for the 0 purpose of supporting combustion should be heated somewhat before it enters the kiln. The radiation of heat from the combustion within the kiln, through the closure, is ordinarily very great and the cause of much inconvenience and suffering for men who are obliged to work at the kiln. It has been proposed in some cases to prevent the radiation of the heat through the closure by insulating the same with fire brick, but this makes the closure very heavy and very difficult to handle when it must be moved.

It is the objectof this invention primarily to overcome the difficulties due to such radiation of heat through the ordinary clo- 415 sure without adding materially to the weight thereof and at the same time and in connection with the improved closure to provide for the proper preheating of the air which is introduced into the kiln for the purpose of supporting combustion.

In accordance with the invention the closure is made hollow or provided with air channels through which the air, which preferably has already been heated somewhat by M absorption of heat from the clinker or other burned material in the cooler, is delivered to the kiln, such air being still further heated in its passage through the closure.

Other features of the invention will ap pear more clearly hereinafter, in connection with the following description of the embodiment of the invention which is chosen for illustration in the accompanying drawings in which Figure 1 is a view partly in elevation and partly in vertical section of a hood or closure constructed in accordance with the in vention. Fig. 2 is a detail view in central section on the plane indicated by the line 22 of Fig. 1. Fig. 3 is a detail View in horizontal section on the plane indicated by the line 3-3 of Fig. l.

The kiln a is supported for rotation and is rotated by any usual or suitable means not necessary to be shown or explained herein. It is formed as usual with an outer shell and a fire brick lining. At its end, as at a its diameter is preferably less than the diameter for the greater portion of its length and at the extreme discharge end, as at a the diameter is still further reduced to enter and form the joint with the movable hood or closure 5. The latter is movably supported in position against the lower or discharge end of the kiln, being represented 5 in the drawings as mounted upon suitable wheels 0 and may be provided, as usual, with a suitable nozzle (Z through which the pow-l; dered, gaseous or liquid fuel may be intro-r, duccd. The improved hood or closure, how-E ever, instead of consisting as usual of a single wall, is substantially hollow, being provided, between its front and rear faces, with lateral air channels 6 and with a central chamber 7". The front and rear face walls, the side and top walls and the partition walls by which the several channels and chamber are formed may be made of any suitable material, itbeing possible, by reason of the improved construction of the closure, to use fire brick for the partition and to some extent for lining the walls of metal, since the whole volume of fire brick so used is not great. The channels 0 and the chamber f are open at the bottom, the channels 6, which may be provided each with avsuitable damper c, communicating with the air or dust chamber 9 formed below the closure 6 and the chamber f, which is so placed as to receive the clinker or other burned material discharged from the cylinder a, permitting the discharge of such material through its bottom by which the clinker or other material may be directed into asuitable cooler (not illustrated). The opening in the bot tom of the chamber f may be regulated by placing therein one or another of several plates, one of which is shown at F, provided with openings of different size, the lower part of the chamber being accessible through a suitable door f provided for the purpose in the front face of the closure. The lateral channels 6 may unite in the upper part of the closure so as to direct the air which rises through them into the kiln through the opening 6 in the rear wall of the closure around the fuel nozzle (Z. Supplemental curved plates 6 are secured to the front wall of the hood, thereby giving the air currents curved paths. The plates 0" may be continued by extensions or deflecting dampers e for the purpose of further directing the air currents.

Short tubular collars 6 may be provided for insertion between the bottom of the hood and the floor upon which it rests to direct the air from the dust chamber 9 into the lateral channels a and central chamber f respectively, such guards being removed before the hood is itself withdrawn from its position against the end of the cylinder (4.

The nozzle or fuel pipe (Z, which forms a part of the fuel injector through which the powdered, liquid or gaseous fuel is injected into the kiln, is preferably adjusted so as to permit the fuel blast to be properly directed in the kiln. The fuel pipe or injector (Z is mounted on a ball and socket joint, having at its rear end a spherical enlargement cl which fits into a spherical socket (Z secured to the front wall of the hood. A bail lever (Z secured to the trunnions of the nozzle (Z enables the operator to swing the nozzle upward or downward as may be desired, the nozzle being retained in adjusted position by clamping screw (Z which passes through the hinged socket (Z into the supporting casting and clamps the socket upon the spherical bearing (Z of the nozzle. Lateral adjustment of the nozzle is permitted by making the trunnions of the spherical bearing (Z of sufiicient length and by providing proper clearance around them and around the nozzle itself.

In order that the air which is supplied to the kiln through the hood or closure may be heated before it reaches the hood, as well as in its passage through the hood, the air may be supplied under pressure as from a fan or other suitable source and conducted first through asuitable cooler, where it absorbs heat from the clinker or other burned material which as noted before may be delivered into the cooler through the chamber f, and then passes in part into the chamber g from which it passes into the channels a and thence into the kiln, and in part in a direction contrary to that of the clinker into the chamber f and thence into the kiln. The air which is thus delivered into the kiln, although preheated to some extent, is nevertheless cool as compared with the temperature at the end of the kiln and, absorbing the heat which would otherwise be radiated through the hood in the passage of the air therethrough, prevents the radiation of heat outward from the hood to an undesirable degree while it is its-elf further heated before its entrance into the kiln. The quantity of air admitted into the kiln is controlled by the dampers e in the lateral channels 6, the quantity of air which passes into the kiln through the chamber being also regulated by the perforated plates P, which may have openings of such size as to permit the clinker to fall through, or thev may be lifted from time to time to permit the chamber f to be cleared of clinker.

It will be obvious that various changes in details of construction and arrangement may be made to suit different conditions of use without departing from the spirit of the invention.

I claim as my invention:

A hood for a rotary kiln having in its rear wall a recess to receive the end of the kiln and in its front wall an opening, a central chamber formed between its front and rear faces having a curved top wall, a fuel supply pipe disposed within the opening in the front wall and discharging into the chamber, the fuel pipe, the chamber and the kiln being substantially coaxial, and the curved top wall of the chamber lying in juxtaposition to the fuel pipe, a second chamber formed in the hood extending downwardly throughout the hood to permit the discharge of clinker from the kiln therethrough, and the admission of air into the kiln therethrough, independent channels formed in the hood one at each side of the discharge chamber and curved laterally adjacent their upper ends to permit the discharge of air into the first named chamber, curved deflectors disposed within the channels adjacent said first named chamber to direct the air into intimate association with the fuel as it passes through the first named chamber into the kiln, and means to support the hood movably to facilitate its movement required.

This specification signed and witnessed this 18th day of October, A. D. 1910.

AXEL scHArrER.

Signed in the presence of P. Holman Barns, A. M. PERMIN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

